Water vapour pressure above saturated salt solutions at low temperatures

1. The construction, maintenance and calibration of a sensitive instrument capable of making numerous vapour-pressure measurements within humidity gradients by the dew-point method is described. 2. Coefficients of diffusion of water vapour in air, calculated from observed vapour-pressure gradients and measured rates of evaporation agree with theoretical and other experimental values in still air. 3. Apparent coefficients in wind speeds between 10 and 100 cm/s were significantly lower than those in still air. 4. This finding, together with the performance of the dew-point probe, is discussed in relation to its possible use in the study of evaporation from animals and plants.

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The Thermal Comfort of Premature Newborn versus Water Vapour Pressure

IFMBE Proceedings - World Congress on Medical Physics and Biomedical Engineering, September 7 - 12, 2009, Munich, Germany ◽

10.1007/978-3-642-03885-3_170 ◽

2009 ◽

pp. 612-615

Author(s):

C. F. Oldenburg Neto ◽

M. F. Amorim ◽

S. H. Silva ◽

M. A. Gariba

Keyword(s):

Thermal Comfort ◽

Water Vapour ◽

Vapour Pressure ◽

Water Vapour Pressure ◽

Premature Newborn

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Properties of hydrated TiO2 and SiO2 nanoclusters: dependence on size, temperature and water vapour pressure

Nanoscale ◽

10.1039/c8nr07262k ◽

2018 ◽

Vol 10 (45) ◽

pp. 21518-21532 ◽

Cited By ~ 3

Author(s):

Andi Cuko ◽

Antoni Macià Escatllar ◽

Monica Calatayud ◽

Stefan T. Bromley

Keyword(s):

Water Vapour ◽

Systematic Study ◽

Vapour Pressure ◽

Water Vapour Pressure ◽

Nano Silica

The stabilities and properties of globally optimised (TiO2)M(H2O)N and (SiO2)M(H2O)N clusters with M = 4–16 and a range of N/M ratios are studied with respect temperature and water vapour pressure. Our systematic study provides a comparative reference for understanding hydration of nano-silica and nano-titania.

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Study of the reaction CaSO4.½H2O (β-hemihydrate) = CaSO4 (β-soluble anhydrite)+½H2O in the temperature range 20–100° C

Mineralogical Magazine and Journal of the Mineralogical Society ◽

10.1180/minmag.1965.034.268.28 ◽

1965 ◽

Vol 34 (268) ◽

pp. 327-345 ◽

Cited By ~ 5

Author(s):

J. D. C. McConnell

Keyword(s):

Water Vapour ◽

Vapour Pressure ◽

Physical Adsorption ◽

Linear Increase ◽

Water Vapour Pressure ◽

Hydration Reaction ◽

Temperature Range ◽

Dehydration Reactions ◽

Adsorption Of Water ◽

Hydration And Dehydration

SummaryA thermogravimetric vacuum microbalance has been used to study the reaction between β-soluble anhydrite and water vapour in the temperature range 20–100° C. Equilibrium water-vapour pressures for the hydration reaction in this temperature range were determined directly and have been compared with available data obtained by Kelly, Southard, and Anderson (1941) in the temperature range 80–120° C. The kinetics of the hydration and dehydration reactions have also been studied in a series of isothermal experiments with varying water-vapour pressure. These experiments indicate that in a vapour-pressure range close to the equilibrium value very low rates for both hydration and dehydration are observed. Outside this range of vapour pressures both hydration and dehydration rates increase suddenly and show an approximately linear increase with imposed water-vapour pressure.At low temperatures (25° C) the dehydration reaction has an associated activation energy of approximately 10 kcal mole−1. In the same temperature range additional, physical adsorption of water vapour by the specimen was noted.

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Techniques and Applications for Imaging Biological Samples in a Low Vacuum Environmental Scanning Electron Microscope

Microscopy and Microanalysis ◽

10.1017/s1431927600029986 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 782-783

Author(s):

C. J. Gilpin.

Keyword(s):

Water Vapour ◽

Biological Samples ◽

Vapour Pressure ◽

Water Vapour Pressure ◽

Environmental Scanning ◽

Sample Collection ◽

Electron Microscopes ◽

A Site ◽

Scanning Electron Microscopes ◽

Scanning Electron

Of all the commercially available scanning electron microscopes which operate at “low vacuum” the ESEM is the most suitable for examining biological samples. in order to maintain samples with liquid water present the specimen chamber must be capable of operating at a pressure of at least 4.6 Torr (611 pascals) of water vapour pressure (the vapour pressure of water at 0°C). Use of lower pressures or a chamber gas other than water vapour will result in evaporation of water from the sample at a rate dependant on the partial pressure difference between the sample and its surrounding environment. Tables of relative humidity as a function of water vapour pressure and temperature are readily available to calculate desired settings for the microscope.One of the difficulties associated with examining fresh biological material is the need to have the microscope and sample available in the same location at the same time.If sample collection occurs at a site remote from the microscope inevitable necrotic changes will occur before examination can be carried out.

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